The present invention is generally directed to surgical instruments or tools. In particular, the present invention relates to surgical instruments and systems that include wristed electrosurgical end effectors and methods of performing a surgical procedure. The surgical instruments can advantageously be used in robotically controlled minimally invasive surgical operations.
Minimally invasive medical techniques are intended to reduce the amount of extraneous tissue which is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. One effect of minimally invasive surgery, for example, is reduced post-operative hospital recovery times. Because the average hospital stay for a standard open surgery is typically significantly longer than the average stay for an analogous minimally invasive surgery, increased use of minimally invasive techniques could save millions of dollars in hospital costs each year. While many of the surgeries performed each year in the United States could potentially be performed in a minimally invasive manner, only a portion of the current surgeries use these advantageous techniques due to limitations in minimally invasive surgical instruments and the additional surgical training involved in mastering them.
Minimally invasive robotic surgical or telesurgical systems have been developed to increase a surgeon's dexterity and avoid some of the limitations on traditional minimally invasive techniques. In telesurgery, the surgeon uses some form of remote control, e.g., a servomechanism or the like, to manipulate surgical instrument movements, rather than directly holding and moving the instruments by hand. In telesurgery systems, the surgeon can be provided with an image of the surgical site at the surgical workstation. While viewing a two or three dimensional image of the surgical site on a display, the surgeon performs the surgical procedures on the patient by manipulating master control devices, which in turn control motion of the servo-mechanically operated instruments.
The servomechanism used for telesurgery will often accept input from two master controllers (one for each of the surgeon's hands) and may include two or more robotic arms on each of which a surgical instrument is mounted. Operative communication between master controllers and associated robotic arm and instrument assemblies is typically achieved through a control system, such as those described in U.S. Pat. Nos. 6,364,888 and 6,424,885, the full disclosures of which are incorporated herein by reference. The control system typically includes at least one processor which relays input commands from the master controllers to the associated robotic arm and instrument assemblies and back from the instrument and arm assemblies to the associated master controllers in the case of, e.g., force feedback or the like. Mapping of the hand movements to the image displayed from the image capture device can help provide the surgeon with more control over movement of the surgical instruments. One example of a robotic surgical system is the DA VINCI® system available from Intuitive Surgical, Inc. of Sunnyvale, Calif.
The servo-mechanically driven linkage is sometimes referred to as a robotic surgical manipulator. Exemplary linkage arrangements for use as a robotic surgical manipulator during minimally invasive robotic surgery are described in U.S. patent application Ser. No. 10/957,077 and U.S. Pat. Nos. 6,758,843 and 5,800,423, the full disclosures of which are incorporated herein by reference. These linkages make use of a parallelogram arrangement to hold an instrument having a shaft. Such a manipulator structure can mechanically constrain movement of the instrument so that the instrument pivots about a point of spherical rotation positioned in space along the length of the rigid shaft. By aligning this pivot point with the incision point to the internal surgical site (for example, with a trocar or cannula at an abdominal wall during laparoscopic surgery), an end effector of the surgical instrument can be moved without imposing dangerous forces against the abdominal wall. Alternative manipulator structures are described, for example, in U.S. Pat. Nos. 6,702,805; 6,676,669; 5,855,583; 5,808,665; 5,445,166; and 5,184,601, the full disclosures of which are incorporated herein by reference.
A variety of structural arrangements can also be used to support and position the robotic surgical manipulator and the surgical instrument at the surgical site during robotic surgery. Supporting linkage mechanisms, sometimes referred to as set-up joint arms, are often used to position and align each manipulator with the respective incision point in a patient's body. The supporting linkage mechanism facilitates the alignment of a surgical manipulator with a desired surgical incision point. Exemplary supporting linkage mechanism are described in U.S. Pat. Nos. 6,246,200 and 6,788,018 and U.S. patent application Ser. No. 11/043,688, the full disclosures of which are incorporated herein by reference.
One type of end effector which is often advantageous for use with a robotic surgical system is an electrosurgical end effector. A typical electrosurgical treatment instrument is capable of treating tissue of an organism with the use of heat produced by electrical energy while cutting, shearing, grasping, or contacting the tissue. Such instruments are used to carry out treatments, such as incision, coagulation, and the like. Electrosurgical treatment and cutting instruments for both open surgery and manually performed endoscopic surgery have been described. For example, both monopolar and bipolar instruments are described in U.S. Pat. No. 6,102,909, the full disclosure of which is incorporated herein by reference. U.S. Pat. No. 6,132,441 and U.S. Publication No. 2004/0253079, describe robotically actuated surgical device and are also incorporated herein by reference. U.S. Publication Nos. 2004/0267254 and 2002/0188293 describe robotically controlled electrosurgical instruments and are assigned to the assignee of the present application and incorporated herein by reference. While such instrumentation has proven highly effective and advantageous, still further improvements would be desirable. In general, it would be desirable to provide instruments and systems that include wristed electrosurgical end effectors, such as cutting/shearing tools, which are preferably utilized in the course of robotic minimally invasive surgery.